There is a css option when designing a double matrix question, but I don't see how I can e.g. make the two scales in different background colour to make it easier to see the difference between the to scales.

The screenshot shows my question. I want the first scale to be in a light grey colour while the second scale should be displayed in a darker one. Possible? Is it even possible to increase the gap between the two scales or insert some kind of divider, e.g. a vertical line?